* The Wisdom of Cats (2003)
* The Cat's Meow:A Celebration of the Human-Feline Bond (2004)
* Cat People:Why We Love Them and They Tolerate Us (2005)
* The Joy of Cats:A Collection of Wit, Wisdom, and Purring (2006)
* Jeg kan have Cheezburger? En guide til internetalderen (2007)
* LOLcats:The Book:The Original Book That Inspired the Internet Phenomenon (2008)
* The Purrrfect Cat:A Field Guide to Understanding Your Cat's Unique Personality (2009)
* The Zen of Cats:A Path to Enlightenment Through Feline Meditation (2011)
* The Art of the Cat:Celebrating the Artistry of Cats (2012)
Skønlitteratur:
* The Cat's Pyjamas:A Novel of Suspense (2010)
* Katten der kom til jul (2012)
* Katten der vidste for meget (2014)
Børnebøger:
* Katten der reddede julen (2015)
* Katten der fandt et hjem (2017)
* The Cat Who Got Lost (2019)